Definition

Colorado tick fever is an infection that is spread to humans by the bite of an infected tick.

Causes

Colorado tick fever is caused by the Colorado tick fever virus. Humans can get the virus through the bite of an infected tick. The Rocky Mountain wood tick is the main carrier of the Colorado tick virus in the United States (US). This tick can be found in the western US states (not just in Colorado). It can be found in areas above 5,000 feet in elevation.

The virus is also carried by other small mammals, including ground squirrels, porcupines, and chipmunks. There have been reports of rare cases of Colorado tick fever caused by exposure in a laboratory setting and a blood transfusion.

Tick Bite

Colorado tick fever is transmitted through the bite of an infected tick.

Risk Factors

Living or traveling in mountain forest areas at altitudes above 5,000 feet in the western United States (such as Colorado, Utah, Wyoming, Idaho, Montana, Oregon)

Being in these areas between April and July

Symptoms

Symptoms usually appear 4-5 days after a tick bite occurs and may last for 3 weeks.

Colorado tick fever may cause:

High fever

Chills

Severe headache

Pain behind the eyes

Sensitivity to light

Muscle pain

Lethargy

Abdominal pain

Vomiting

Nausea

Rash

Diagnosis

Your doctor will ask about your symptoms and medical history. A physical exam will be done.

Tests may include the following:

Blood tests to identify the virus

Blood tests to identify antibodies for the virus

Other blood tests

Treatment

There is no specific treatment for Colorado tick fever. Complications are extremely rare and include aseptic meningitis, encephalitis, and hemorrhagic fever. The fever and pain may be treated with acetaminophen and other pain relief medications. It is important to stay hydrated by drinking enough fluids. It is believed that immunity against re-infection occurs after exposure to Colorado tick fever.

Prevention

To help reduce your chance of Colorado tick fever:

Avoid tick-infested areas, especially during warmer months.

Wear light-colored clothing to better locate a crawling tick.

Tuck pants into socks when in tick-infested habitats.

Use tick repellents.

Regularly inspect and remove ticks from your body and your child’s body when in tick-infested habitats.

Remove ticks using fine-tipped tweezers by grasping the tick close to the skin’s surface and pulling upward steadily.

Disinfect tick bites with soap and water.

Revision Information

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

The health information in this Health Library is provided by a third party. Cartersville Medical Center does not in any way create the content of this information. It is provided solely for informational purposes. It does not constitute medical advice and is not intended to be a substitute for proper medical care provided by a physician. Always consult with your doctor for appropriate examinations, treatment, testing, and care recommendations. Do not rely on information on this site as a tool for self-diagnosis. If you have a medical emergency, call 911.